Process for manufacturing cast aluminum alloy plate

Abstract

A twin-roll continuous casting method that controls occurrence of casting defects in a center part of plate thickness, for Al—Mg series aluminum alloy, a material featuring a wide temperature range for solid and liquid phases coexistence. In the method of manufacturing an Al—Mg series aluminum alloy cast plate, the plate contains Mg in a predetermined amount and has a relatively thick plate size, while casting is performed by a twin-roll type continuous casting method. Twin rolls have a roll diameter, and the rolls have a circumferential velocity. The circumferential length from points where molten metal starts contact with the rolls to kiss points is a solidification distance, and the roll gap at the kiss points is equal to the thickness of the cast plate. Specific relations among the above factors are maintained, and the continuous casting operation is carried out while satisfying such relations.